Indoor Air Quality

Inadequate Air Flow

If not enough outdoor air enters your home, pollutants rise.  Because of this, health issues may occur.   For this reason, it is important that homes and buildings have adequate means of air flow (ventilation ) The amount of leaks in and out of the home also plays a role in levels of contaminants.  

Source Control

Usually the most effective way to improve indoor air quality is to eliminate individual sources of pollution or to reduce their emissions.

Some sources, like those that contain asbestos, can be sealed or enclosed; others, like gas stoves, can be adjusted to decrease the amount of emissions. In many cases, source control is also a more cost-efficient approach to protecting indoor air quality than increasing ventilation because increasing ventilation can increase energy costs.

Improved Ventilation

For most indoor air quality problems in the home, source control is the most effective solution.

Another approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors.

Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room where the fan is located and also increase the outdoor air ventilation rate.

It is particularly important to take as many of these steps as possible while you are involved in short-term activities that can generate high levels of pollutants — for example, painting, paint stripping, heating with kerosene heaters, cooking, or engaging in maintenance and hobby activities such as welding, soldering, or sanding. You might also choose to do some of these activities outdoors, if you can and if weather permits.

Pollutant Sources

• Asbestos
• Biological Pollutants
• Carbon Monoxide (CO)
• Formaldehyde/Pressed Wood Products
• Lead (Pb)
• Nitrogen Dioxide (NO2)
• Pesticides
• Radon (Rn)
• Indoor Particulate Matter
• Secondhand Smoke/ Environmental Tobacco Smoke
• Stoves and Heaters
• Fireplaces and Chimneys
• Volatile Organic Compounds (VOCs)

Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home. Some of these designs include energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers).

The introduction of outdoor air is one important factor in promoting good air quality. Air may enter a home in several different ways, including:

• through natural ventilation, such as through windows and doors
• through mechanical means, such as through outdoor air intakes associated with the heating, ventilation and air conditioning (HVAC) system
• through infiltration, a process by which outdoor air flows into the house through openings, joints and cracks in walls, floors and ceilings, and around windows and doors.